OSRAM’s infrared Power TOPLED with stack chip technology

OSRAM Opto Semiconductors achieved this tremendous increase in performance thanks to its stack technology for thin-film chips. Last year, the stack technology was introduced to large-scale 1 mm² chips, featuring a serial connection of two, instead of one, p-n junctions and attaining almost double the performance. This unique technology has been applied to chips with an edge length of 300 µm for the SFH4250S. As Harald Feltges, Marketing Manager for Infrared Components at OSRAM Opto Semiconductors, points out: “With this combination of well-proven chip design and standard packages, our customers can make use of our enlarged portfolio of powerful IR emitters without having to change their design.” The new Stack Power TOPLED allows pulsed operation up to 1 A pulse current, reaching 220 mW/sr radiant intensity and 700 mW total radiant flux.

Applications where compact lighting units illuminate large areas with infrared light can benefit significantly from this new component. A typical example is 3D TV sets: The synchronization of shutter glasses with the television picture is achieved by powerful IR emitters that illuminate the area in front of the TV set up to a distance of 7 m. According to Harald Feltges, “The new Stack Power TOPLED almost halves the number of required IR-LEDs per TV set, or it dramatically improves the range of existing designs, respectively.”

With a wavelength of 850 nm, the emitted light of the SFH4250S is not visible to the naked eye, nor does it interfere with a TV’s remote control, which works at about 950 nm. Many computer games make use of the 3D technology, too, benefiting from these new IR emitters. This increased IR power also generates advantages in vehicle safety systems, mainly in seat occupancy detection systems for airbag activation and driver monitoring systems to enable fatigue detection (Drowsy Driver System).

The stack technology for thin-film chips has been proved and tested in many applications, from night vision systems in vehicles to sensors in mobile end user devices, which are particularly well suited to benefit from the excellent efficiency of stack chips. By expanding its stack technology to the Power TOPLED series, OSRAM Opto Semiconductors consolidates its leading position in the field of powerful IR emitters. The new Power TOPLED SFH 4250S is available now.